// Hypnosis Spiral
//
// by Mario Klingemann
// mario@quasimondo.de
// http://incubator.quasimondo.com
//
// Reuse of this widget in your own projects
// is free and permitted as long as proper 
// credit is given by leaving this text
// block in the code.


float c=600.0;
void setup() {
  size (600,200);
  noStroke();
}

void loop()
{
  int w2=width/2;
  int h2=height/2;
  int w1=width-1;
  int h1=height-1;
  float maxdist=sqrt(h2*h2+w2*w2);
  float dx,dy,angle,dist;
  int d,p;
  c+=(mouseY-h2)/32.0;
  float w=4.0+(mouseX/5.0);
  background(0); 
  for (int y=0;y<height;y++){
    dy=float(h2-y);
    for (int x=0;x<width;x++){
    dx=float(w2-x);
    angle=c+atan2(dy,dx)*w/PI;
    dist=sqrt(dx*dx+dy*dy);
    d=int((angle+dist)/w);
    if (( d & 1 )==1){
         pixels[x+y*width]=0xffffffff;
      }
    }
  }
  
}